Plant Growth and Development

AIPMT 2015 (Cancelled)MCQEasy📈 Topic in 50% papers+4−1

Ques. 1AIPMT 2015 (Cancelled)

What causes a green plant exposed to the light, on only one side, to bend towards the source of light as it grows?

Light stimulates plant cells on the lighted side to grow faster.
Auxin accumulates on the shaded side, stimulating greater cell elongation there.
Green plants need light to perform photosynthesis.
Green plants seek light because they are phototropic.

Answer

(2) Auxin accumulates on the shaded side, stimulating greater cell elongation there.

Solution

Unilateral light causes auxin produced at the shoot tip to move towards the shaded side.

⇒ Auxin accumulates on the shaded side and stimulates greater cell elongation there.

∴ The shaded side grows faster than the lighted side, and the shoot bends towards the light (phototropism); as per NCERT, auxin was first isolated from the tips of coleoptiles of oat seedlings in such phototropism experiments.

Answer: (2)

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Ques. 2AIPMT 2015 (Cancelled)

Typical growth curve in plants is

stair-steps shaped
parabolic
sigmoid
linear.

Ques. 3AIPMT 2014

Dr. F. Went noted that if coleoptile tips were removed and placed on agar for one hour, the agar would produce a bending when placed on one side of freshly-cut coleoptile stumps. Of what significance is this experiment?

It made possible the isolation and exact identification of auxin.
It is the basis for quantitative determination of small amounts of growth-promoting substances.
It supports the hypothesis that IAA is auxin.
It demonstrated polar movement of auxins.

Ques. 4AIPMT 2014

A few normal seedlings of tomato were kept in a dark room. After a few days they were found to have become white-coloured like albinos. Which of the following terms will you use to describe them?

Mutated
Embolised
Etiolated
Defoliated

Ques. 5AIPMT 2014

Which one of the following growth regulators is known as 'stress hormone'?

Abscisic acid
Ethylene
GA3
Indole acetic acid

Ques. 6NEET 2013

During seed germination its stored food is mobilized by

ABA
gibberellin
ethylene
cytokinin.

Ques. 7NEET 2013 (Karnataka)

The pineapple which under natural condition is difficult to blossom has been made to produce fruits throughout the year by application of

NAA, 2,4-D
Phenyl acetic acid
Cytokinin
IAA, IBA.

Ques. 8NEET 2013 (Karnataka)

Which of the following best illustrates "FEEDBACK" in development ?

As tissue (X) develops, it secretes something that induces tissue (Y) to develop
As tissue (X) develops, it secretes something that slows down the growth of tissue (Y)
Tissue (X) secretes RNA which changes the development of tissue (Y)
As tissue (X) develops, it secretes enzymes that inhibit the development of tissue (Y)

Ques. 9AIPMT 2012 (Mains)

Through their effects on plant growth regulators, what do the temperature and light control in the plants?